What do you get for your money? That's the question everyone looking to buy a piece of tech asks themselves. It also happens to be the question our new recurring feature will try and answer. Is it worth spending extra, or do you get what you need with the cheaper models? Every month, we'll look at some of the cheapest and most expensive products in a given category, testing each to see what their limits are and help you figure out when you can cheap it out, and when you need to lay down some extra cash to get what you need. First up:

High/Low: Gaming PCs
——————–

These rigs are built to handle the incredible demands modern games put on them, rendering state-of-the-art graphics quickly and smoothly to create a realistic gaming experience. At least, that's the theory. The conventional wisdom is that a cheap PC will produce a jerky, low-resolution image that ruins the immersive effect of modern games.

However, we found that a $700 computer was more than capable of running one of the most demanding games out there at high resolution, and that most gamers don't need to spend more than this.

To run our tests, we asked custom PC maker iBuyPower to build us two rigs – one with a budget of about $700, and the other a spare-no-expense $5,000 gaming beast. They sent us two computers: the AMD FM2 F-series A2 and the Erebus XLV3.

In the cheap corner is the smaller A2 with red trim. It's built around a low-end AMD processor and a low-end $113 NVidia graphics card (we upgraded from integrated graphics as this is a gaming PC). This system certainly looks flashy, with a matte black case and a big side window that showcases a number of glowing LEDs on the fans. In the expensive corner is the $5,000 Erebus XLV3. This tricked-out beast of a machine is a gamer's dream. It comes with dual GeForce GTX680 graphics cards, 32GB of fast RAM, and a 6-core i7 processor. All of this comes packaged in a matte-black case with a side window that shows off the Koolance water cooling system's green glowing pipes. It looks like the offspring of the 2001 monolith and a cyberpunk nuclear reactor, and has the low-end purr of fans that sound more like a Ferrari than a fast PC.

And fast it is: The Erebus managed an average of 138 frames per second (fps) in the built-in benchmark of Bioshock Infinite. That's with every graphical bell and whistle turned on, and running at 1920 by 1200 pixel resolution on a 24-inch monitor. In Portal 2, we found the same sorts of figures, with a recorded demo running at the same resolution and the highest possible graphics settings burning through at an incredible 826.19 fps. That gives you some insight into the incredible computing power that modern graphics cards harness, especially when you run two of them side by side in SLI mode.

The A2, by contrast, produced smaller numbers, reaching just 37 fps in the Bioshock Infinite benchmark, and 278.36 fps in Portal 2 (one anti-aliasing setting was different here because the graphics card did not support 16x AA).

Going on the numbers alone you would assume the more expensive computer was far, far better – bigger numbers are better, right?

Well, no. The numbers are more than a little misleading here. Once you reach 60 frames per second, any increase is pretty much meaningless because your monitor can't display them. (Almost all monitors can only show 60 frames each second.) Most people won’t be able to spot a problem so long as the game can still manage 30 fps or more. Pushing frame rates above this is really only an exercise in theory that's meant to impress nerds and tech reviewers. It has no impact on the playability of the game.

In the end, it comes down to the gaming experience, and here we found very little difference between the two systems. On both computers, Bioshock Infinite was very playable, with smooth motion and the full cinematic experience. We did notice some odd graphics glitches on the cheaper PC, and the game got a bit laggy during a large firefight with lots of explosions going off at once. However, these glitches and slowdowns vanished when we turned off some of the more complex eye candy, specifically turning the texture filtering down to normal or high.

Ultimately, the differences we found between a $700 PC and a $5,000 one were negligible. The truth of the matter is that even a relatively cheap computer is capable of running one of the most demanding games at its highest quality settings without choking or becoming unplayable. (One caveat here: It does require a dedicated graphics card, as integrated graphics would still struggle with Bioshock and other games.)

So why spend $5 grand on a gaming machine? Well, the Erebus system has a lot more processing power, more memory, more disk space, more... well, everything. That will make a big difference for other uses (such as video editing), but for gaming these extra parts make little difference.

The only reason you would need a computer like this for gaming is if you want to use multiple monitors for games such as flight simulators. The dual graphics cards allow you to run up to six monitors at once, which would make for an excellent cockpit simulation. But that's an extreme case, and most gamers will be more than happy with the performance of the much cheaper computer. This is definitely a case where the low end works: It provides great gaming bang for the buck, and for a hell of a lot fewer bucks.